![]() | This article's factual accuracy may be compromised due to out-of-date information.(October 2016) |
The Blob is a large mass of relatively warm water in the Pacific Ocean off the coast of North America that was first detected in late 2013 and continued to spread throughout 2014 and 2015. [1] [2] It is an example of a marine heatwave. [3] Sea surface temperatures indicated that the Blob persisted into 2016, [4] but it was initially thought to have dissipated later that year.
By September 2016, the Blob resurfaced and made itself known to meteorologists. [5] The warm water mass was unusual for open ocean conditions and was considered to have played a role in the formation of the unusual weather conditions experienced along the Pacific coast of North America during the same time period. [1] The warm waters of the Blob were nutrient-poor and adversely affected marine life. [6]
In 2019 another scare was caused by a weaker form of the effect referred as "The Blob 2.0" [7] and in 2021 the appearance of "The Southern Blob" at south of the equator near New Zealand has caused a major effect in South America, particularly Chile and Argentina. [8] [9]
The Blob was first detected in October 2013 [10] and early 2014 by Nicholas Bond and his colleagues at the Joint Institute for the Study of the Atmosphere and Ocean of the University of Washington. It was detected when a large circular body of seawater did not cool as expected and remained much warmer than the average normal temperatures for that location and season. [11]
Bond, then the state climatologist for Washington, coined the term the Blob, with the term first appearing in an article in the monthly newsletter of the Office of the Washington State Climatologist for June 2014. [12]
Initially the Blob was reported as being 500 miles (800 km) wide and 300 feet (91 m) deep. [1] It later expanded and reached a size of 1,000 miles (1,600 km) long, 1,000 miles (1,600 km) wide, and 300 feet (91 m) deep in June 2014 when the term the Blob was coined. [12] [13] [14] The Blob now hugged the coast of North America from Mexico to Alaska and beyond, stretching more than 2,000 miles (3,200 km), and formed three distinct patches: the first, off the coast of Canada, Washington, Oregon, and northern California, a region known to oceanographers as the Coastal Upwelling Domain; [15] [16] the second in the Bering Sea off the coast of Alaska; and the third and smallest off the coast of southern California and Mexico. [11] [17]
In February 2014, the temperature of the Blob was around 2.5 °C (4.5 °F) warmer than what was usual for the time of year. [13] [18] A NOAA scientist noted in September 2014 that, based on ocean temperature records, the North Pacific Ocean had not previously experienced temperatures so warm since climatologists began taking measurements. [14]
In 2015 the atmospheric ridge causing the Blob finally disappeared. The Blob vanished shortly after in 2016. However, in its wake are many species that will take a long time to recover. [19] Although the Blob is gone for now, scientists predict that similar marine heat waves are becoming more common due to the Earth's warming climate. [19] Residual heat from the first blob in addition to warmer temperatures in 2019 lead to a second Blob scare. However, it was quelled by a series of storms that cooled the rising temperatures. [20]
The immediate cause of the phenomenon was the lower than normal rates of heat loss from the sea to the atmosphere, compounded with lower than usual water circulation resulting in a static upper layer of water. Both of these are attributed to a static high pressure region in the atmosphere, termed the Ridiculously Resilient Ridge, which was formed in the spring of 2014. [21] [22] The lack of air movement impacted the wind-forced currents and the wind-generated stirring of surface waters. These in turn influenced the weather in the American Pacific Northwest from the winter of 2013–2014 onward and may have been associated with the unusually hot summer experienced in the continental American Pacific Northwest in 2014. [18]
The reason for the phenomenon remains unclear, but it is speculated to partially be human caused climate change. Some experts consider that the wedge of warm water portends a cyclical change with the surface waters of the mid-latitude Pacific Ocean flipping from a cold phase to a warm phase in a cycle known as the Pacific decadal oscillation (PDO). [1] This poorly-understood change happens at irregular intervals of years or decades. During a warm phase, the west Pacific becomes cooler and part of the eastern ocean warms; during the cool phase, these changes reverse. [23] Scientists believe a cold phase started in the late 1990s and the arrival of the Blob may have been the start of the next warm phase. The PDO phases may also be related to the likelihood of El Nino events. [1]
NASA climatologist William Patzert predicts that if the PDO is at work here, there will be widespread climatological consequences and southern California and the American south may be in for a period of high precipitation with an increase in the rate of global warming. Another climatologist, Matt Newman of the University of Colorado, does not think the Blob fits the pattern of a shift in the PDO. He believes the unusually warm water is due to the persistent area of high pressure stationary over the northeastern Pacific Ocean. Dan Cayan of the Scripps Institution of Oceanography is unsure about the ultimate cause of the phenomenon, but states "there's no doubt that this anomaly in sea surface temperature is very meaningful". [1]
Sea surface temperature anomalies are a physical indicator which adversely affect the zooplankton (mainly copepods) in the northeast Pacific Ocean and specifically in the Coastal Upwelling Domain. Warm waters are much less nutrient-rich than the cold upwelling waters which were normal until recently off the Pacific coast. [24] This resulted in reduced phytoplankton productivity with knock-on effects on the zooplankton which fed on it and the higher levels of the food chain. [18] [25] Species lower in the food web that prefer colder waters, which tend to be fattier, were replaced by warmer water species of lower nutritional value. [26]
The Northwest Fisheries Science Center in Seattle predicted reduced catches of coho and Chinook salmon, a major contributing factor being the raised temperatures of seawater in the Blob. [24] Salmon catches dropped as the fish migrated away having found low levels of zooplankton. [11] [27]
Thousands of sea lion pups have starved in California which lead to forced beachings. [28] Thousands of Cassin's auklets in Oregon have starved due to lack of food. [28] [18]
Animals that favored warm southern waters were spotted as far north as Alaska, examples being the warm water thresher sharks (Alopias spp) and ocean sunfish (Mola mola). [14] [28] In the spring of 2016, acres of Velella velella were reported in the waters south of the Copper River Delta. [29]
The discovery of a skipjack tuna (Katsuwonus pelamis), primarily a fish of warm tropical waters, off Copper River, in Alaska, 200 miles (320 km) north of the previous geographic limit, and a dead sooty storm-petrel (Oceanodroma tristrami), a species native to Northern Asia and Hawaii, along with a few brown boobies (Sula leucogaster) in the Farallon Islands of California, besides other such records, has led marine biologists to worry that the food web across the Pacific is in danger of disruption. [28]
Biologists from the University of Queensland observed the first-ever mass bleaching event for Hawaiian coral reefs in 2014, and attributed it to the blob. [30]
Research from the University of Washington found positive temperature anomalies in the northeast Pacific Ocean (upper ~100 m, greater than 2.5 °C, with temperatures at the coast below normal) for the winter period of 2013–2014. Heat loss from the ocean during the winter was suppressed. During spring and summer 2014 the warmer sea surface temperature anomalies reached coastal waters. The anomaly may have had a significant effect on the unusually warm summer of 2014, with record high temperatures over parts of land in the Pacific Northwest. Offshore sea surface temperatures (SSTs) in the northeast Pacific for the month of February were the greatest at least since the 1980s, possibly as early as 1900. Additionally they found anomalous sea surface pressure SSP, with a peak magnitude approaching 10 hPa, a record high value for the years of 1949–2014. [18]
Canadian senior climatologist David Phillips noted in May 2015 about the coming winter season, "If that blob continues, if it stays warm ... and then you add to that El Nino, it may complement each other and then it may be the year winter is cancelled." [31]
El Niño is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific, including the area off the Pacific coast of South America. The ENSO is the cycle of warm and cold sea surface temperature (SST) of the tropical central and eastern Pacific Ocean.
La Niña is an oceanic and atmospheric phenomenon that is the colder counterpart of El Niño, as part of the broader El Niño–Southern Oscillation (ENSO) climate pattern. The name La Niña originates from Spanish for "the girl", by analogy to El Niño, meaning "the boy". In the past, it was also called an anti-El Niño and El Viejo, meaning "the old man."
Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water from deep water towards the ocean surface. It replaces the warmer and usually nutrient-depleted surface water. The nutrient-rich upwelled water stimulates the growth and reproduction of primary producers such as phytoplankton. The biomass of phytoplankton and the presence of cool water in those regions allow upwelling zones to be identified by cool sea surface temperatures (SST) and high concentrations of chlorophyll a.
El Niño–Southern Oscillation (ENSO) is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics. The warming phase of the sea temperature is known as El Niño and the cooling phase as La Niña. The Southern Oscillation is the accompanying atmospheric component, coupled with the sea temperature change: El Niño is accompanied by high air surface pressure in the tropical western Pacific and La Niña with low air surface pressure there. The two periods last several months each and typically occur every few years with varying intensity per period.
An ocean current is a continuous, directed movement of seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, shoreline configurations, and interactions with other currents influence a current's direction and strength. Ocean currents are primarily horizontal water movements.
Sea surface temperature (SST), or ocean surface temperature, is the ocean temperature close to the surface. The exact meaning of surface varies according to how we measure it. It is between 1 millimetre (0.04 in) and 20 metres (70 ft) below the sea surface. Sea surface temperatures greatly modify air masses in the Earth's atmosphere within a short distance of the shore. Local areas of heavy snow can form in bands downwind of warm water bodies within an otherwise cold air mass. Warm sea surface temperatures can develop and strengthen cyclones over the Ocean. Experts call this process tropical cyclogenesis. Tropical cyclones can also cause a cool wake. This is due to turbulent mixing of the upper 30 metres (100 ft) of the ocean. Sea surface temperature changes during the day. This is like the air above it, but to a lesser degree. There is less variation in sea surface temperature on breezy days than on calm days. Ocean currents, such as the Atlantic Multidecadal Oscillation, can affect sea surface temperatures over several decades. Thermohaline circulation has a major impact on average sea surface temperature throughout most of the world's oceans.
The Kuroshio Current, also known as the Black or Japan Current or the Black Stream, is a north-flowing, warm ocean current on the west side of the North Pacific Ocean basin. It was named for the deep blue appearance of its waters. Similar to the Gulf Stream in the North Atlantic, the Kuroshio is a powerful western boundary current that transports warm equatorial water poleward and forms the western limb of the North Pacific Subtropical Gyre. Off the East Coast of Japan, it merges with the Oyashio Current to form the North Pacific Current.
Chionoecetes is a genus of crabs that live in the northern Pacific and Atlantic Oceans.
The Chinook salmon is the largest and most valuable species of Pacific salmon. Its common name is derived from the Chinookan peoples. Other vernacular names for the species include king salmon, Quinnat salmon, Tsumen, spring salmon, chrome hog, Blackmouth, and Tyee salmon. The scientific species name is based on the Russian common name chavycha (чавыча).
The Pacific decadal oscillation (PDO) is a robust, recurring pattern of ocean-atmosphere climate variability centered over the mid-latitude Pacific basin. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of 20°N. Over the past century, the amplitude of this climate pattern has varied irregularly at interannual-to-interdecadal time scales. There is evidence of reversals in the prevailing polarity of the oscillation occurring around 1925, 1947, and 1977; the last two reversals corresponded with dramatic shifts in salmon production regimes in the North Pacific Ocean. This climate pattern also affects coastal sea and continental surface air temperatures from Alaska to California.
The coho salmon is a species of anadromous fish in the salmon family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon or "silvers". The scientific species name is based on the Russian common name kizhuch (кижуч).
The Alaska Current is a southwestern shallow warm-water current alongside the west coast of the North American continent beginning at about 48-50°N. The Alaska Current produces large clockwise eddies at two sites: west of the Haida Gwaii and west of Sitka, Alaska.
Ocean deoxygenation is the reduction of the oxygen content in different parts of the ocean due to human activities. It occurs firstly in coastal zones where eutrophication has driven some quite rapid declines in oxygen to very low levels. This type of ocean deoxygenation is also called "dead zones". Secondly, there is now an ongoing reduction in oxygen levels in the open ocean: naturally occurring low oxygen areas are now expanding slowly. This expansion is happening as a consequence of human caused climate change. The resulting decrease in oxygen content of the oceans poses a threat to marine life, as well as to people who depend on marine life for nutrition or livelihood. Ocean deoxygenation poses implications for ocean productivity, nutrient cycling, carbon cycling, and marine habitats.
There are many effects of climate change on oceans. One of the main ones is an increase in ocean temperatures. More frequent marine heatwaves are linked to this. The rising temperature contributes to a rise in sea levels. Other effects include ocean acidification, sea ice decline, increased ocean stratification and reductions in oxygen levels. Changes to ocean currents including a weakening of the Atlantic meridional overturning circulation are another important effect. All these changes have knock-on effects which disturb marine ecosystems. The main cause of these changes is climate change due to human emissions of greenhouse gases. Carbon dioxide and methane are examples of greenhouse gases. This leads to ocean warming, because the ocean takes up most of the additional heat in the climate system. The ocean absorbs some of the extra carbon dioxide in the atmosphere. This causes the pH value of the ocean to drop. Scientists estimate that the ocean absorbs about 25% of all human-caused CO2 emissions.
The "Ridiculously Resilient Ridge", sometimes shortened to "Triple R" or "RRR", is the nickname given to a persistent anticyclone that occurred over the far northeastern Pacific Ocean, contributing to the 2011–2017 California drought. The "Ridiculously Resilient Ridge" nickname was originally coined in December 2013 by Daniel Swain on the Weather West Blog, but has since been used widely in popular media as well as in peer-reviewed scientific literature.
Haida Eddies are episodic, clockwise rotating ocean eddies that form during the winter off the west coast of British Columbia's Haida Gwaii and Alaska's Alexander Archipelago. These eddies are notable for their large size, persistence, and frequent recurrence. Rivers flowing off the North American continent supply the continental shelf in the Hecate Strait with warmer, fresher, and nutrient-enriched water. Haida eddies are formed every winter when this rapid outflow of water through the strait wraps around Cape St. James at the southern tip of Haida Gwaii, and meets with the cooler waters of the Alaska Current. This forms a series of plumes which can merge into large eddies that are shed into the northeast Pacific Ocean by late winter, and may persist for up to two years.
The 1997–1998 El Niño was regarded as one of the most powerful El Niño–Southern Oscillation events in recorded history, resulting in widespread droughts, flooding and other natural disasters across the globe. It caused an estimated 16% of the world's reef systems to die, and temporarily warmed air temperature by 1.5 °C (2.7 °F) compared to the usual increase of 0.25 °C (0.45 °F) associated with El Niño events. The costs of the event were considerable, leading to global economic losses of US$5.7 trillion within five years.
The cold blob in the North Atlantic describes a cold temperature anomaly of ocean surface waters, affecting the Atlantic Meridional Overturning Circulation (AMOC) which is part of the thermohaline circulation, possibly related to global warming-induced melting of the Greenland ice sheet.
A marine heatwave is a period of abnormally high ocean temperatures relative to the average seasonal temperature in a particular marine region. Marine heatwaves are caused by a variety of factors, including shorter term weather phenomena such as fronts, intraseasonal, annual, or decadal modes like El Niño events, and longer term changes like climate change. Marine heatwaves can have biological impacts on ecosystems at individual, population, and community levels. MHVs have lead to severe biodiversity changes such as coral bleaching, sea star wasting disease, harmful algal blooms, and mass mortality of benthic communities. Unlike heatwaves on land, marine heatwaves can extend for millions of square kilometers, persist for weeks to months or even years, and occur at subsurface levels.
Ocean dynamical thermostat is a physical mechanism through which changes in the mean radiative forcing influence the gradients of sea surface temperatures in the Pacific Ocean and the strength of the Walker circulation. Increased radiative forcing (warming) is more effective in the western Pacific than in the eastern where the upwelling of cold water masses damps the temperature change. This increases the east-west temperature gradient and strengthens the Walker circulation. Decreased radiative forcing (cooling) has the opposite effect.